We use Joy once a week. The trick is to do a really good triple rinse and use a vinegar rinse if you come up with dandruff. Also, don't pour the Joy onto the topline. Instead. dissolve it in a bucket of water, make lots of soapsuds , and use a brush to scrub it in the hair. Then use hair conditioner, but remember to rinse that out also. Make sure you rinse all the hidden spots really well. I like to use a horse sweat blade to push out the rinse water. Makes rinsing easier and less to blow out. Also we use Sullivans Clear Choice at shows when we shampoo more often. If you do get a bad case of dandruff, use one of the really fine toothed cat combs to get it loosend up and then blown out.